Method of making synthetic pile fabrics



United States Patent 2,914,836 METHOD or MAKING smrg m ABRICS 2 Claims. eras-112) more economically 'a'syntheticpilefabi'ic.

It is the primary object of this invention to prepare suitable pile fabrics in a more economical manner than has heretofore been possible.

In accordance with this invention a pile fabric is 'inventionrelates to'a novel rnethod of preparing prepared by the steps comprising (1) treating a flat tricot knit fabric in which a high percentage of the staple fiber is a synthetic organic fiber, with a methylsilicone fluid in which at least a major proportion of the organic radicals are methyl radicals, (2) napping the fabric, (3) passing the fabric'near an electrostatic bar to cause the napped fibers to stand out, (4) again napping the fabric to develop the desired pile, and then finishing the fabric.

Applicant has found that when a tricot knit fabric is first treated with a silicone then napped and passed near an electrostatic bar that the fabric is placed in condition for the production of an excellent pile material by further napping. Equivalent results are not obtained when the silicone is applied after the first napping or after passing near the electrostatic bar.

The process of this invention can be carried out on conventional textile equipment and inasmuch as a flat tricot knit fabric can be employed the process is much cheaper than has heretofore been used in the preparation of synthetic pile fabrics.

Fabrics which are suitable for use in this invention are those which contain a high percentage of synthetic staple fibers such as the fibers obtained from synthetic cellulose such as cellulose triacetate; synthetic polyesters such as polymers of terephthalic acid and ethylene glycol; synthetic acrylic polymers such as polyacrylonitrile (Orlon) and copolymers of acrylonitrile and vinylidene chloride (Dynel) and synthetic vinylic polymers such as copolymers of vinylchloride and vinylidene chloride; copolymers of vinylacetate and vinylchloride; and synthetic polyamides such as polymers of hexylenediamine and adipic acid. In addition, the fabric can contain natural fibers such as cotton, wool, linen and the like. The precise amount of synthetic fiber in the fabric can vary widely but in general at least is desirable.

The knit fabric can be treated with the methylsiloxane in any desired manner. Thus, the siloxane may be sprayed on the fabric or the fabric may be passed through a solution or an emulsion of the siloxane.

' When a solution or an emulsion of the siloxane is employed it is best to dry the siloxane before napping. This may be done by heating the fabric at a suitable temperature such as 350 F. or below.

The siloxanes which are suitable for use in this invention include any fluid methylpolysiloxane such as dimethylsiloxane; methylhydrogensiloxane; copolymers of ,dimethyland trimethylsiloxane; copolymers of dimeth- 2,914,836 Ratented Dec. 1, 1959 "ice the methylsiloxanes can also contain minor amounts of other hydrocarbon substituted siloxanes suchas phenylmethylsiloxane, diethylsiloxane, vinylmethyl siloxane, ethylmethylsiloxane, ethylhydrogensiloxane, ,octadecylmethylsiloxane and tolylmethylsiloxane.

After treatment .with the siloxane the fabric is napped in "the conventional manner and is then passed near an electrostatic .bar. "The'bar will have a charge opposite to the charge on the fabric. (This causes the napped fibers to standout 'from'the surface of the fabric.

The (fabric is then passed'through another napping station where the napping is .carried out to the extent necessaryto givethev desired pile. If desired, ,a plurality ofrnapping stations. may ;be employed 'at'this point; The fabric'is then ready'for finishing.

The finishing of the fabric will depend-upon'the type of fabric employed. In general, the finishing entails passing the fabric through a heating station so as to fix the fabric. This process is conventional with the preparation of synthetic fabrics. Prior or subsequent to this heating the fabric may be treated with additional organesiloxane compositions in order to impart a better hand and other desirable features to the fabric. Other finishing steps can include shearing the pile to the desired height and running the fabric face up through an ironing machine of the Furtex type. This latter step imparts added luster to the fabric.

If desired, organic resins-such as melamine formaldehyde and urea formaldehyde resins can be applied to the fabric in order to increase the dimensional stability thereof. These resins can be employed along with the organosiloxane either before or after napping or they can be applied separately to the fabric.

If desired, the organosiloxanes employed herein may contain curing catalysts so that they cure during the drying step. However, it is not essential that the siloxane be cured or that the siloxane be capable of curing under the conditions of the manufacture of the fabric. However, it is preferred that a curable siloxane be employed, such as, for example, mixtures of dimethylsiloxane and methylhydrogensiloxane.

Specific examples of the process of this invention are given by way of illustration and not by way of limitation.

Example 1 nap to stand up. The fabric was then further napped to give an extensive pile and thereafter heated above 250 F. to fix the fabric. The resulting fabric had a full luxuriant pile.

Example 2 A suitable pile fabric is obtained when the above fabric is treated with a 2% emulsion of a fluid copolymer of dimethylsiloxane, trimethylsiloxane and monomethylsiloxane.

Example 3 Equivalent results are obtained when the process of Example 1 is carried out with polyamide fabrics (nylon), and with fabrics composed of mixtures of 50% wool and 50% terephthalic acid-ethylene glycol polyester fibers (Dacron).

' 3 Example 4 mer of 10 mol percent vinylmethylsiloxane, 10 mol percent 'phenylmethylsiloxane, 10 mol percent diethyl siloxane, 30 mol percent dimethylsiloxane and 40 mol percent methylhydrogensiloxane, is employed in the process of Example 1.

That which is claimed is:

1. A method of preparing a synthetic pile fabric which comprises the steps of (1) treating a fat tricot knit fabric consisting essentially of staple fibers, a high percentage of which is synthetic organic fiber, with a methylsilicone 2. The method of claim 1 wherein the methylsilicone fluid is a mixture of a methylsiloxane of the formula where n has a value from 1.9 to 2.1 inclusive and a methylhydrogenpolysiloxane.

References Cited in the fileof this patent "2,758,355 Kradoska Aug, 14, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nea 2,914,836 December 1, 1959' I Richard H, Montgomery It is hereby certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line' 10 for "a fat tricot knit fabric" read a flat tricot knit fabric .Signed and sealed this 10th day of May 1960,

(SEAL Attest? KARL Hg AXLINE Attesting Officer ROBERT C. WATSON Commissioner of Patents 

1. A METHOD OF PREPARING A SYNTHETIC PILE FABRIC WHICH COMPRISES THE STEPS OF (1) TREATING A FAT TRICOT KNIT FABRIC CONSISTING ESSENTIALLY OF STAPLE FIBERS, A HIGH PERCENTAGE OF WHICH IS SYNTHETIC ORGANIC FIBER, WITH A METHYLSILICONE FLUID IN WHICH AT LEAST A MAJOR PROPORTION OF THE ORGANIC RADICALS ARE METHYL RADICALS, (2) NAPPING THE FABRIC SO TREATED, (3) PASSING THE FABRIC NEAR AN ELECTROSTATIC BAR TO CAUSE THE NAPPED FIBERS TO STAND OUT, (4) AGAIN NAPPING THE FABRIC TO DEVELOP THE DESIRED PILE, AND THEN FINISHING THE FABRIC. 